We own two HM700U cameras with the Canon 14X lens. We've tried adding Tiffen 82mm filters to the front of the lens hood but they don't seem to fit well as the thread sizes don't seem to match. Can you recommend an appropriate filter for this combo?

The lens barrel of the standard Canon 14x lens is 72mm. Filters should be screwed into the lens barrel directly, not into the hood. Once installed, the filters should not interfere with the hood.